Means for distilling acids.



W. HOP.

MEANS FOR DISTILLING AGIDS. V APPLICATION FILED 813M229, 191s.

Patented June 9, 1914.

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WILLY HUI, 0i FRAITKFORT-ON-THE-MAIN, GERMANY.

MEANS FOR DI Specification of Letters Patent.

STILLING ACIDS.

Patented June 9, 1914-.

Application filed September 29, 1913. Serial No. 792,454.

To all whom it may concern Be it known that I, WILLY Hor, suojcct of the German Emperor, residing at 4 Elkenbachstrasse, Frankfort-on-the-Main, Ger-- many, have invented certain new and useful Improvements in Means for Distilling Acids, of which the following is a specification.

This invention relates to an improved.

means for distilling acids and is particularly applicable to the distillation of sulfuric acid.

Hitherto in the urification of acids such as sulfuric acid, tie acid has been evaporated in glass or porcelain retorts and the vapors cooled in tubes of similar material. This method was, however, extremely difficult owing to breakage of the retorts and condenser and owing to the purification of the retort-s from. residues. Moreover, the fuel was badly utilized since the retorts had to be heated in sand baths Violent ebullition of the liquid also occurred, thus fre quently causing destruction of the vessels, while the condenser easily fractured on a sudden supply of larger quantities of vapor. Finally the closing of the retorts anduthe connection of the diilerent parts gave rise to difiiculties as the larger cemented joints were liable to leak in consequence of the different coellicients of heat and permit of the escape of larger quantities of unpleasant sulfuric acid yapors. The distilling plants required particularly great care in order to always maintain the retorts properly filled as the provisioiifof a water gage was impos sible. The use of quartz glass overcame these disadvantages in part in so far as the .sbreakage through expansion and contraction was considerably diminished, but the ar-' rangement hitherto used did not admit of continuous distillation.

By the use of tubular evaporating vessels of quartz glass or the like, a considerable advance in the distillation of acids may be obtained inasmuch as it is possible to con struct an apparatus in which continuous distillation can be carried out without the danger of brealrages. The use of tubular heating; surfaces for evaporating apparatus is indeed not new perse but as a rule these tubular elements are entirely filled with this means a violent ebullition takes place owing to the vapor bubbles in the tubes, which necessitates the provision of special vapor chambers for separating the liquid. Moreover, the impurities collect in considerable quantity in the evaporating space and can only be removed by the use oif comparatively complicated apparatus. All these difficulties are however avoided in a very simple manner if the tubes are laid substantially horizontal or slightly inclined and only small quantities of liquid allowed to continuously trickle therethrough in such a manner that the greater part of the liquid is evaporated on passing through the tubes and if an outlet is provided at a suitable part of the tube for discharging the impurities and the unvaporized liquid, while the vapors pass alone farther direct to the condensing tube and 'urc condensed therein.

In the accompanying drawings such an arrangement is diagrammatically illustrated by way of example.

The liquid to be purified enters at a and is evaporated in the tube 1), the vapors conydensing in the tube 0. A channel d collects the condensed liquid from a row of parallel tubes and conveys the liquid to a collecting vessel. The impurities escape at e together with the impure liquid and are collected in the channel After the impurities are separated from the acid the rest of the acid is again returned for distillation.

Any kind of fuel may be utilized for heoting purposes but preferably oil fuel should be employed or electric heating where the current is cheap, since a perfectly uniform supply of heat is thereby insured and the liquid toibe distilled and which is uniformly supplied is also entirely uniformly converted into vapor.

A particular advantage of the present orrangement is that when the su ply of heat varies, pure acid will always be obtained, since the excess supply of impure acid escapes from the apparatus at e. It was indeed to be feared that with the poor conductivity of heat and the extremal small heating surface, the evaporatin yiel would contrary that considerable quantities of liquid can he evaporated up to 1000 kilograms of sulfuric acid per square centimeter of tubular surface in 2 1: hours, so that the efficiency is great with comparatively small plants. The proposed arrangement is also a great improvement since it is possible in the first place with reliability to so lay the tubes, that internal strains due to the unequal expansion of the quartz glass and masonry cannot take place, which is for ex be too small, but it has been ound on the ample impossible when using retorts and condenser Worms, and moreover'joints in the apparatus can be entirely obviated or limited to small spigot'andsocket joints. As a perfect jointing material for quartz glass has not hitherto been found it is very important that large joints should be ob viatedwhich would permit the vapors to escape and by driving out the cement give rise to fracture of the cemented quartz glass parts.

1 I claim a 1. An apparatus for distilling acid comprising a highly refractory tube positioned so that .acid continuously supplied thereto at one end will trickle therethrough, means forheating a portion of said tube adjacent its supply end, the tube being provided at an intermediate point in its length with an outlet for discharging unvaporized liquid and impurities, and a condenser for the liquid vaporized in the heated section of the tube and passing said outlet.

2. An apparatus for distilling-acid com-v prising a highly refractory tube positioned so that acid continuously supplied thereto at one end. Will trickle therethrough, means prising a highlyrefractory tube of highly tube and. passing said outlet.

for heating a portion of said tubeadjacent its supply end, the tube being provided at an intermediate point in its length with an outlet for discharging unvaporize liquid and impurities, and means for cooiing the tube beyond said outlet.

3.; An apparatus for distilling acid comprising a highly refractory tube is quartz glass positioned so that acid continuously supplied at one end "will trickle there-l through, means for heating portion said tube adjacent its supply end, thetube having beyond the portion thus heated an outlet for discharging unvaporized liquid. and impurities, and a condenser for tln uid vaporized in the tube and passing outlet. I 4. An apparatus for distilling acid ceraacidic glass of the nature of quartz glass positioned so that acid continuously supplied at one end :Will trickle 'therethrough, means for heating a portion of said tube adjacent its supply end, the tube havin beyond the portion thus heated an outlet or discharging unvaporized liquid and impurities, and a condenser for the liquid vaporized in the 55 5. An. apparatus for distilling acid. com prising a highly refractory tube m, quartz glass positioned so that acid coutinu ly' I supplied at one end will trickle t erethrough, means for vheating a portion oii said tube, the latter having'beyond said heated portion an outlet for discharging vaporized liquid and impurities, and means for cooling a portion of the tube beyond said outlet, to condense the liquid vaporized in passing through the heated section of the tube. v

In testimony whereof l have ai'l' signature in presence of two witnus.

WILLY- ii 1) ed my.

Witnesses lean Biinnmonn. JEAN GRUND. 

